Games OSX or Bootcamp?

Overall, would it be better to buy Windows games and play them on XP via Bootcamp or to buy the Mac versions of games like COD 2 and Doom 3 and play other non-Mac games on Windows?

Depends on what you plan on having on at all times. If you want to leave OS X running, and just boot into XP when need be, I'd rather get the Mac version of the game than the XP one. Problem is that Mac games tend to be more expensive than Win games (could just be the small selection of stores here though)

since the topic has been brought up... do games run well on those emulators that trick the program into thinking your running windows when in fact you're not?